Polyfluoro alkanamidoalkyl phosphates



United States Patent 3,188,346 PQLYFLUORO ALKANAMEGALKYL PHGSPHATES AlanK. Mackenzie, Bedding, Conn, assignor to E. I. du Pont de Nemours andCompany, Wilmington, Del, a corporation of Delaware No Drawing. FiledBee. 8, 1961, Ser. No. 158,121 3 Claims. (Cl. 260-461) This inventionrelates to novel processes for rendering solid materials oil-repellentand to the novel oil-repellency agents for use in such processes. Bysolid materials hereinabove I mean water-insoluble materials customarilyemployed in the manufacture of articles of utility, for instance textilefabric, textile yarns, leather, paper, plastic sheeting, Wood, ceramicclays, as Well as manufactured articles prepared therefrom such asarticles of apparel, wall paper, paper bags, cardboard boxes, porousearthenware, etc. By oil-repellency, for the purpose of definiteness, Ishall refer hereinafter to the quality of repelling, under the standardtests herein discussed, a light mineral oil such as a commercial liquidhydrocarbon or a vegetable oil such as peanut oil. But as a generalproposition the materials treated according to this invention are foundto possess repellency to oils, greases and fats generally, regardless oftheir origin (as for instance, mineral, vegetable or animal kingdom) ortheir consistency.

Heretofore, oil-repellency generally has been attained by high-costprocesses or materials, and the end results have not been fullysatisfactory. Oil-resistant glassinetype paper is costly to manufacture,and it is readily penetrated by water and water-vapor. Oil-repellencygained by coating paper or cardboard requires a separate operation andthe protective surface film is easily broken when the paper is creasedor folded, whereby the oil-repellency is lost.

It is a primary object of this invention to impart oilrepellency toWater-insoluble solid materials by treatment with an aqueous bath ofoil-repellency agents. A further object is to provide certain novelcompounds which are useful for the aforegoing purposes. Gther objectsand achievements of this invention will become apparent as thedescription proceeds.

Now, according to this invention the aforegoing principal objects areacomplished by treating water-insoluble materials with aqueous solutionsof polyfluoro-alkanamido-alkyl phosphates and removing the excess Waterfrom the treated material. The polyfluoro-alkanamido-alkyl phosphatescontemplated in this invention are novel compounds and may be defined bythe formula venience, in free acid form but are preferably used in the(2) Bis[2 (pentadecafiuorooctanamido)ethyl] phos- (1) 2 (N ethyl 7Hdodecafluoro-heptanamido)ethyl phosphate:

(2) Bis[2 (pentadecafluoro octanamido)ethyl] phosphate:

[F (G F2)7C ONHCHzCH2O] P O (OH) (3) Bis[2 (Npropyl-pentadecafluoro-octanamido)ethyl] phosphate:

[F (C F910 O-N-CHgCHgOhP O (OH) (4) Bis [2 (9H hexadecafiuorononanamido) ethyl] phosphate:

[H(C F2)3C ONHCHzCH2O]2P O (OH) (5) 6 (N propylheptadecafiuoro-nonanamido)hexyl phosphate:

F (CFmC ON-(CHz)sO-PO (0H),

(6) l2 (N butyl 13H-tetracosafluoro-tridecanamido)- dodecyl phosphate:

11 0 Fzhzo ON(CH2)1Z O PO(OH)Z The above compounds can be prepared byreacting the corresponding polyfluoro-alkanamido alkanols withphosphorus oxychloride or with phosphorus pentoxide, essentially asdescribed in US. Patent 2,597,702. As in that patent, the products maybe isolated as free acid (ll/i=i-l) and then converted, byneutralization with the appropriate base into an alkali-metal (say,sodium or potassium), ammonium or susbtituted ammonium salt. Asconvenient bases for obtaining substituted ammonium salts may be usedcommonly available, water-soluble, primary, secondary or tertiary aminessuch as methylamine, diethylarnine, monoethanolarnine, diethanolamine,morpholine, triethanolamine and bis(3-hydroxypropyl)- amine.

Other methods of synthesis are also available and are summarized at theend of this specification.

The requisite initial polyfluoro-alkanamido alkanols themselves may beprepared by converting the corresponding polyfluoroalkanoic acids to theacid chlorides, which are then reacted with amino alkanols. Details ofthe preparation of a representative member of this group of compounds isgiven in Example 1 below.

The treatment of textile fibers or other water-insoluble materials withpolyfluoro-alkanamido-alkyl phosphates according to this invention maybe achieved by any of the ordinary procedures, for instance padding,spraying or brushing, using aqueous solutions of said agents, and theqauntity thereof put into the aqueous bath will usually be calculated todeposit on the fiber a weight of the agent equal to from 0.05% to 3% byWeight of the fiber. In padding procedures, the amount of moisture lefton the fiber after squeezing will, of course, be taken into account.

The preparation of the requisite aqueous solutions may be facilitated byfirst dissolving the phosphate agent in an organic solvent, such asacetone, methanol, or ethanol, followed by dilution with Water, or asolution of the free 7 acid phosphate in an oragnic' solvent may bediluted with water-soluble linear polymer containing cationic nitrogenwhereby to endow said material with the power of exhausting thephosphate from the aqueous bath. The treatment then assumes the aspectof an exhaust bath procedure,

and the qauntity of phosphate put into the bath is essentially theentire'quantity that it is desired to deposit on the fiber (or othermaterials). l

Further details on this aspect of my invention are given in my copendingapplication Serial No. 53,884 (filed Sep- Patented June 8, 1965 3 tember6, 1960), now U.S. Patent No. 3,112,241, but for the sake ofcompleteness, the essential features thereof are repeated here.

As examples of commercially available cationic polymeric materialssuitable for use in this invention may be mentioned:

(a) The polymers or copolymers of quaternary derivatives or acid saltsof esters of a dialkylamino alcohol and acrylic acid or methacrylicacid. Specific dialkyl amino alcohols suitable for forming these estersinclude Z-(dimethylamino)ethanol, 2-(diethylamino)ethanol, 2-(dipropylamino)ethanol, 2 (N methyl-N-cyclohexylamino)ethano1,S-(diethylamino)propanol and 4-(diethylamino)butanol. The esters areprepared according to the method set forth in US. Patent 2,138,763, thenquaternized, for example, in an aqueous solution of dimethyl sulfate,and the resulting quaternary ammonium salt is polymerized, or two ormore of them are copolymerized, by known procedure. The esters may alsobe converted to acid salts with acids such as acetic, formicorhydrochloric, and polymerized or copolymerized by known procedure. (Seefor instance US. Patent 2,138,762.)

Preferred cationic compounds of this group are the polymers derived fromthe dimethyl sulfate quaternization product or from the acetic acidaddition salt of 2- (dimethylamino)ethyl methacrylate and 2(diethylamino)ethyl methacrylate.

(b) Water-soluble urea resins possessing cationic N- atoms, for instanceone prepared from urea, formaldehyde, tetraethylene-pentamine, andhydrochloric acid as described by Suen, in Polymer Processes, edited bySchildknecht (Interscience, 1956), page 343.

(c) Melamine-formaldehyde resins possessing cationic N-atoms, forinstance the acid colloid prepared from formaldehyde, melamine, andhydrochloric acid as described by Suen, loc. cit, at pages 315, 344.

(d) The quaternized or acid salts or polymerized ethyleneimine, forinstance those having a molecular weight of 30,000 to 40,000.

(e) Cationically modified nitrogen-containing starches, certainrepresentatives of which appear in commerce.

The above agents themselves may be applied to the desired solidmaterials by ordinary procedures, for instance by padding, exhaustion,spraying or brushing, using aqueous solutions of the agents.

The quantity of cationic agent added may vary from 0.05% to 10% on theweight of the material being treated, while that of the phosphate, asalready mentioned, may be from 0.05% to 3%. The optimum amount willdepend upon such factors as the nature of the material, and in the caseof paper pulp on the nature of the pulp, the particular cationicmaterial selected, the composition of the phosphate, and the degree ofoil-repellency desired. As a rule, a given combination of agents inspecified amounts produces a greater effect on on bleached kraft pulpthan on bleached kraft or bleached sulfite pulp. Of the phosphates, theammonium or substltuted ammonium salts are more effective than the freephosphoric acid, and the w-F compounds (X -F) are more 'eifective thanthe corresponding w-H compounds (X=H). Also, thebis-polyfluoro-alkanamidoalkyl phosphates are more potent than the monocompounds.

The order of treatment of the solid material with thepolyfiuoro-alkanamido-alkyl phosphate and polymeric cationicN-containing material is immaterial, provided care is taken to eliminateor minimize contact between the two agents except when either of them isin contact with the solid material being treated. This means that thecationic agent may be applied first and then after a little time to,permit complete exhaustion of the agent onto the material'being treated,the fibers of a pulp for example, 'the polyfluoro-alkanamido-alkylphosphate may be applied. Or the reverse sequence may be followed, witha time interval to allow for exhaustionot the phosphate compound ontothe fiber. Or again, the two agents may be fed simultaneously throughseparate pipes into the vessel or pipe containing the pulp, providedvigorous agitation (or turbulent flow in the case of a pipe) is appliedto insure rapid contact of each agent with the pulp, thus minimizingtime of contact between the two agents when not in contact with thepulp. When a pulp is to be diluted in a fan pump or head box, however,the phosphate and cationic N-containing treating agents may be addedseparately to the stream of water with which the dilution is effected.

Without limiting this invention, the following examples are given toillustrate the preferred mode of operation. Parts mentioned are byweight.

Example J.Preparatin 0f the polyfluo roalkanamido-alkyl phosphates Amixture of 82.8 parts of perfluorooctanoic acid (C F -COOH) and 47 partsof benzotrichloride is heated under nitrogen at 120 C. for about 18hours. Fractiona1 distillation of the reaction mass yieldsperfiuorooctanoyl chloride, having a boiling range of 133 to 134.5 C. atatmospheric pressure. To 44.9 parts of this chloride is added 15.3 partsof ethanolamine, with gradual raising of the temperature to 75 to 80 C.The mass is cooled to room temperature, washed with aqueous hydrochloricacid and with water, dried by azeotroping with benzene, andrecrystallized twice from benzene. The resultant N (2hydroxyethyl)perfluorooctanamide, C F -CONH-CH CH OH, melts at 62 to 65C. and has an infrared spectrum corresponding to the N-hydroxyalkylamidestructure.

To a dry benzene-ethyl ether solution of 9 parts of the aboveN-(Z-hydroxyethyl)perfluorooctanamide is added a dry benzene solution of1.53 parts of phosphorus oxychloride and 1.58 parts of pyridine, withagitation at 5 to 10 C. The mixture is heated to distill 01f ethylether, and is then held at reflux temperature for one hour. The productis bis(perfluorooctanamidoethyl) phosphochloridate, which may berepresented by the formula To the reaction mass containing the aboveintermediate are now added 1.1 parts of water and 0.8 part of pyridine,and refluxing is continued for another hour. The mass is then cooled toroom temperature, and allowed to settle into layers. The upper,benzene-water layer, is decanted off, and the lower layer is washed fourtimes with 10 parts of water, then;mixed with 80 parts of benzene, anddehydrated by azeotropic distillation. Anhydrous ammonia is now bubbledthrough the hot benzene solution to saturation, and the mass is cooledto room temperature. The solid product is filtered off and dried. Itconstitutes a mixture of ammonium monoandbis[2-(pentadecafluoro-octanamido)ethyl] phosphate, containing by weightof the bis-ester as determined by fluorine analysis.

When the same procedure is repeated except for starting with9H-hexadecafiuoro-nonanoic acid,

a mixture of ammonium monoand bis[2-(9H-hexadecafiuoro-nonamido)ethyl]phosphate is obtained, falling within Formula I above and having anaverage y-value of 1.76, based upon fluorine analysis.

Example 2.-Treatment of paper pillp Four parts of dry, unbleached kraftpulp are agitated vigorously in a vessel containing 300 parts of water,and 4 parts of an aqueous 0.5% solution of the polymer of dimethylsulfate-quaternized Z-(diethylaminoethyl) methacrylate are added. (Thisprovides 0.5% of the polymer on the dry weight of the pulp.) Agitationis con tinned for five minutes (or longer), and then is added 1 part ofa 0.4% water solutionof a mixture of monoand bis [2-(pentadecafluoro-octanamido)ethyl] phosphate, ammonium salt, having ay-value of about 1.75, as prepared in Example 1. (This quantitycalculates to 0.1% on the weight of the dry pulp.) After additionalstirring for five minutes or more, the slurry of pulp is conveyed to thescreen of a paper making machine, and a sheet of paper is formed and issubsequently dried on a rotary drier in the usual way.

When the above process is repeated,'except for employing 2 or more partsof the 0.4% solution of the mixed ammonium (polyfluorooctanamido)ethylphosphate, paper having 0.2% or more of the agent on the fiber isobtained.

Paper thus prepared may be evaluated for its oil-repellency rating bythe Nujol-n-heptane test described more fully in my said copendingapplication Serial No. 53,884, new U.S. Patent No. 3,142,241, under theheading A. Testing of surface-treated, sheet material (also in U.S.=Patent 2,95 8,613 except that the swatches of fabric there mentionedare replaced here by sheets of the paper to be evaluated.

When thus tested, three papers prepared according to the above exampleand having respectively 0.1%, 0.2% and 0.3% of the agent on the iiberwere found to possess the following ratings:

(P=amount of polyfiuoro-alkanamido-alkyl phosphate in the paper,expressed as a percentage on the weight of the dry pulp.)

Oil-repellency P, percent rating It will be noted that with as little as0.1% of the phosphate in combination with 0.5% of the polymericquaternary derivative a definite oil-repellency is imparted to thepaper, and with 0.2% and 0.3% of the phosphate a high order ofoil-repellency is achieved.

Example 3.--Treatment of paper pulp Using the same paper pulp, the samecationic polymer and the same procedure and proportions as in Example 2,except using as polyfluoro agent a mixture of ammonium monoand bis[2(9H-hexadecafiuoro-nonanamido)ethyl] phosphate having a y-value of 1.76,as obtained at the end of Example 1, and oil-repellent paper of the samehigh qualities as in Example 1 is obtained.

Samples of paper prepared according to this example and in which thephosphate deposit was 0.3% and 0.4%, respectively, based on the weightof the fiber, were evaluated for oil-repellency rating according to TestB of my aforesaid copending application. This test measures theresistance of the paper to penetration by peanut oil by noting the timethat it takes for a drop of said oil to pass from the upper surface of ahorizontally supported sheet to its undersurface. The results were asfollows:

(P has same meaning as in Example 2, but refers to It will 'be notedthat a definite oil-repellency is imparted to paper made in theprocedure of this example, particularly when the amount of thepolyfiuoroalkanamido-alkyl phosphate was 0.4% on the weight of thefiber.

Example 4.Treatment of fabrics 100 parts of Various fabrics such ascotton poplin, cotton sateen, wool, nylon, acrylic fiber and polyesterfiber are dipped into an aqueous bath containing 1000 or more parts ofwater and 1 part by Weight of the acetic acid salt of a polymer obtainedfrom 2-(diethylamin o)ethyl methacrylate. The fabric is agitated in thebath for 5 minutes or more, removed, squeezed, and reimmersed in a bathcontaining 1000 parts or more of water and 1 part of ammonium bis[2 (9Hhexadecafluoro-nonanamido)ethyl] phosphate. The fabric is again agitatedin the bath for 5 minutes or more, removed, squeezed, and air-dried. Thefabrics are found'to have an oil-repellency rating of at least 70 asmeasured by the above referred to heptane-Nujol test.

It will be understood that the details of the above examples may bevaried widely without departing from the spirit of this invention.

Thus, although the polyfluoro-alkanamido-alkyl phosphates are listedsingly in the table hereinabove and may indeed be employed as single,distinct compounds, they may also be used as mixtures of the mono-,bisand hisesters prepared with a single polyfiuoro-alkanamido-alkyl.alkanol. The bis-polyfiuoro-alkanamido-alkyl phosphates are moreeffective than the mono-compounds, and where mixtures are unavoidable,it is preferred to use such mixtures wherein thebis-polyfluoro-alkanamido-alkyl compounds predominate =(i.e. y has anaverage value greater than 1.5). Fully alidated phosphates (-i.e. 3 :3)do not impart oil-repellency, but where a mixture is readily availablethey constitute an inert, harmless diluent for the active monoandbis-compounds. Therefore, mixtures of polyfiuoro-alkanamido-alkylphosphates having a y value greater than 2, say up to y=2.5, are usable.Altogether, compounds having a y-value of 2 are preferred, but mixtureshaving an average y-value between 1.0 and 2.5 can be used.

An alternative method of forming the novel compounds of this inventionis to subject to chlorine oxidation the corresponding bis-(or mixture ofmono and bis)-'(polyfiuoro-alkanamido-alkyl) phosphonates,following theprocedures described by E. N. Walsh in I.A.-C.S., vol. 81, page 3023,for analogous non-fluorinated compounds. These procedures are expressedschematically by the following series of equations, wherein G representsthe radical [m al-c z] as defined in Formula Ihereinabove, R representsthe alkyl radical of any conveniently available dialkyl phosphonate, andthe reactions for producing a bis compound are used to typify theproduction of both his, mono and mixtures of these compounds. {R may be,for instance, methyl, ethyl or phenyl.)

Step J.Formation of the phosphonate. 7

Method A: Ester-interchange with an available dialkyl phosphonate MethodB: Direct reaction with PCl (a) Preparation of phosphite t-amlne 3GOHPO13 (GO)3P +3HC1 '(b) Conversion into phosphonate (The initial compoundGOH used in thesetwo methods may be prepared as in the first paragraphof Example 1.)

Step 2.Oxidation of phosphonate to phosphochlori date: 1

Step 3.Hydrolysis: This is efiected by the aid of water and pyridine asin Example 1. e i

7 I claim as my invention: 1. A compound of the formula wherein X is anatom of the group consisting of hydrogen and fluorine, R is a member ofthe group consisting of hydrogen and lower alkyl, R is a C to C alkylenebridging group, n is an integer from 6 to 12, y is a number of anaverage value from 1.5 to 2.5, and Z is a watersolubilizing cationselected from the class consisting of sodium, potassium, ammonium, loweralkyl ammonium, lower hydroxyalkyl ammonium, and morpholinium.

2. A compound having the formula 3. A compound having the formula [H (CFCONH-CH CH O] P0 ONH References Cited by therExaminer UNITED STATESPATENTS Benning 260-461 Vaughn 260-461 Ahlbrecht 260-4045 Ahlbrecht260-4045 Baumhart et a1 117-161 Brown 117-161 Brace et a1. 260-461 Heine260-461 Cohen 260-461 CHARLES B. PARKER, Primary Examiner.

RICHARD D. NEVIUS, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No,3,188,540 June 8, 1965 Alan K. Mackenzie It is hereby certified thaterror appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 1, line 45, for "acomplished" read accomplished line 65, for "(2]Bis [2- (pentadecafluoro-octanamido)ethyl] phos-" read form of a salt asabove indicated. column 2 line 67, for "qauntity" read quantity column5, line 19,

for "new" read H now line 69,

for "paper" read papers Signed and sealed this 28th day of September1965.

:EAL)

[ICSII RNEST w. swwea EDWARD J. BRENNER testing Officer Commissioner ofPatents

1. A COMPOUND OF THE FOMRULA